1. Field of the Invention
The present invention relates to a transmitting/receiving device and method for a CDMA communication system, and in particular, to a device and method for performing voice and data communication by employing a dedicated control channel.
2. Description of the Related Art
A CDMA (Code Division Multiple Access) mobile communication system has been developed from an existing mobile communication Standard which mainly provides voice communication to the IMT-2000 (International Mobile Telecommunication-2000) Standard which can provide not only the voice communication but also high speed packet data communication. A mobile communication system, employing the IMT-2000 Standard, can provide voice, moving picture, and Internet search services of high quality. The CDMA mobile communication system has communication links between a base station and terminals, and the communication links are divided into a forward link from the base station to the terminal and a reverse link from the terminal to the base station.
The conventional CDMA communication system, though suitable for the voice communication, is unsuitable for the data communication which requires the high speed data transmission and the voice communication of high quality. In order to provide various multimedia services such as the data communication and the voice communication of high quality in addition to the normal voice communication service, the CDMA mobile communication system should employ the communication channels for servicing the voice and the data so as to allocate the channels flexibly at the userNs request.
When the traffic channel is divided into the fundamental channel and the supplemental channel for the data communication service, the fundamental channel should be held consistently to transmit control information, even in the state that the base station is not in communication with the mobile station (i.e., terminal). Accordingly, the conventional CDMA mobile communication system may waste the communication channels, thereby causing the dissipation of the radio capacity.
Further, the conventional CDMA mobile communication system transmits the control message in a fixed frame size. Thus, although the system has the less amount of the transmission data for the control message, it should transmit the data in the fixed frame size, resulting in a lowering of the throughput.
In addition, the conventional CDMA mobile communication system transmits reverse power control bits through the forward fundamental channel. Hence, even though the system has no user data to transmit through the fundamental channel, it should maintain the fundamental channel for the reverse power control, which deteriorates the communication quality.
In the conventional CDMA mobile communication system, a reverse link transmitter consists of a pilot channel, a fundamental channel, a supplemental channel and a control channel. A control channel generator in the conventional CDMA mobile communication system uses only 10 bits per 20 ms frame as input bits and inserts the power control bit thereto at a specified time point. In this case, the amount of the message is too small for the effective control. Besides, since the power control bit is transmitted through the control channel, the system should maintain the control channel for the power control even in case the system has no control message to transmit.
It is therefore an object of the present invention to provide a voice and data transmission/reception device and method for a CDMA communication system.
It is another object of the present invention to provide a device and method for transmitting/receiving control information during voice and data transmission/reception by using a dedicated control channel in a CDMA communication system.
It is still another object of the present invention to provide a device and method for transmitting/receiving control information during voice and data transmission/reception by using a dedicated control channel, wherein a message frame has a structure variable according to the amount of transmission/reception information.
It is further still another object of the present invention to provide a CDMA communication system for transmitting a signaling message and a control information message by using channels that are not occupied.
It is yet another object of the present invention to provide a CDMA communication system in which a reverse transmission device inserts a power control signal into a pilot channel and transmits a control message using a dedicated control channel.
To achieve the above objects, the present invention provides a CDMA communication system including a base station device and a terminal device. The base station device has a forward pilot channel generator for generating a pilot signal, a forward dedicated control channel generator for generating a control message for a forward dedicated control channel, a forward fundamental channel generator for generating a voice signal, and a forward supplemental channel generator for generating packet data. The terminal device has a terminal device including, a reverse dedicated control channel generator for generating a control message for a reverse dedicated control channel, a reverse pilot channel generator for generating a pilot signal by adding a power control signal to the pilot signal, a reverse fundamental channel generator for generating a voice signal, and a reverse supplemental channel generator for generating packet data.